According to Additional Resources, "Spells: The spells in this book are legal for play." That would seem to imply that you can ignore any racial restrictions, since no statement about racial restrictions appears anywhere in the entry for this Player Companion.

Yes, but neither does it say anything about lifting possible restrictions. The gnome spells seem to be allowed for anyone, as that section says “often used by gnomes,” and the individual spells do not mention races.

The half-elf entry is muddier. Not only does it say “half-elves have access to the following spells” in the lede, but it the individual spells also refer to being used by half-elves. Yet they don’t include a specific limiter such as “when cast by a half-elf” or similar. So it’s not really possible to divine the intent with 100% certainty.

According to Additional Resources, "Spells: The spells in this book are legal for play." That would seem to imply that you can ignore any racial restrictions, since no statement about racial restrictions appears anywhere in the entry for this Player Companion.

If the Additional Resources doesn't specify an exception, why wouldn't the restrictions in the companion apply?

According to Additional Resources, "Spells: The spells in this book are legal for play." That would seem to imply that you can ignore any racial restrictions, since no statement about racial restrictions appears anywhere in the entry for this Player Companion.

If the Additional Resources doesn't specify an exception, why wouldn't the restrictions in the companion apply?

Because the Companion itself is somewhat vaguely worded. “Half-elves have access to the following spells” is not quite the same as “Only half-elves have access to the following spells” but neither is it “the following spells are available to any race but are most commonly used by half-elves.”

So, uncertain. And with some books AR goes out of its way to say "this is really available to other races" and sometimes it says "this is really only for this race". So no default position there either.

With the latest update to Additional Resources, the spell False Age from Heroes of the Fringe was legalized. The spell says that "your ability scores increase or decrease as appropriate for your chosen age category." How does this interact with the PFS-specific rule on age categories and ability scores?

The Pathfinder Society-specific ruling is a part of the character creation rules. It does not prevent spells and other effects from temporarily applying the ability score adjustments associated with age.

So a middle aged character that casts False Age to appear Adult instead, would lower his mental scores by 1 and raise his physical scores by 1, since that's the adjustment between adulthood and midle age?

... Which means that venerable characters could appear as Old instead, gaining a hefty +3 to str, dex and con, while getting -1 to cha, int and wis. Seems pretty nice for a spell that lasts 10min per level.

With the latest update to Additional Resources, the spell False Age from Heroes of the Fringe was legalized. The spell says that "your ability scores increase or decrease as appropriate for your chosen age category." How does this interact with the PFS-specific rule on age categories and ability scores?

The Pathfinder Society-specific ruling is a part of the character creation rules. It does not prevent spells and other effects from temporarily applying the ability score adjustments associated with age.

So a middle aged character that casts False Age to appear Adult instead, would lower his mental scores by 1 and raise his physical scores by 1, since that's the adjustment between adulthood and midle age?

... Which means that venerable characters could appear as Old instead, gaining a hefty +3 to str, dex and con, while getting -1 to cha, int and wis. Seems pretty nice for a spell that lasts 10min per level.

Yes, but bear in mind that the “Pathfinder Society-specific ruling” referenced above is that all characters are considered to be adults, you can’t create a venerable (or middle-aged) character.

Characters must be between the ages of adulthood (see Table 7–1 on page 169 of the Core Rulebook) and venerable (see Table 7–2 on page 169 of the Core Rulebook).

You don’t get the stat adjustments, but you can be up to venerable.

EDIT: Though considering all characters to be adult for the purposes of calculating adjustments from the spell might be a good idea. It might also just skew the spell towards being more helpful for casters.

EDIT again: And the follow-up line, which is what’s most relevant here.

Roleplaying Guild Guide wrote:

Do not alter your character’s ability scores as a result of her age category.

You don’t alter your ability scores, but it doesn’t say anything about changing everybody’s age category to Adulthood.

The freedom to have older characters is important for making feats like Breadth of Experience useful. If you couldn’t be older than adulthood, some races that the feat covers would never be able to take it. There may be other things that trigger off age category and not a specific number of years.

I bring all this up just as a request to be cautious with any new ruling that might effectively change how the age categories work, as that could affect many things besides the false age spell.

Huh. You are correct. I was going from memory and conflated "do not alter your ability scores" with "treated as Adult."

Tommi's suggestion could definitely result in some powerful melee characters. Sounds like false age could use a clarification.

. . .Actually, there are also several spells and abilities to temporarily move someone to an older age category - usually as an attack (such as sands of time) - which being venerable would innately protect you from. I'm really trying to think of any situation where choosing to be venerable would be a negative. To prevent shenanigans, maybe instead of clarifications for each ability add in a blanket line in the Guide. Something like:

Potential RPG Guide text wrote:

Do not alter your character’s ability scores as a result of the age category chosen during character creation. For purposes of spells and effects that temporarily alter age categories, your character is treated as being in adulthood regardless of her actual age.

Except that still lets Ezren cast false age for a bump to INT, WIS, and CHA. Though maybe it’s not a cumulative bump like the physical stats. If it’s only ever a +1, that’s not too abusable. If it can go to +3, then even with the hit to CON, I could see some casters doing it for the DC increase on their spells.